1. Field of the Invention
The present invention generally relates to a pixel structure and a fabricating method thereof, and more particularly to a pixel structure and a fabricating method thereof capable of reducing the total number of photomasks.
2. Description of Related Art
A thin film transistor liquid crystal display (TFT-LCD) is mainly composed of a TFT array substrate, a color filter substrate and a liquid crystal layer. The TFT array substrate includes a plurality of TFTs arranged in an array and a plurality of pixel electrodes corresponding to each TFT. The above-mentioned TFT includes a gate, a channel layer, a drain and a source. A TFT and a pixel electrode compose a pixel structure. The TFT serves as a switch device of a liquid crystal display unit (LCD unit).
When fabricating a TFT, one of the most important considerations is to reduce the process steps thereof and thereby reduce the fabricating cost. In particular, the required number of the photomasks needs to be effectively reduced due to the expensive cost of each photomask.
Generally speaking, 4-7 photomasks are usually required to fabricate TFTs. In order to promote the process efficiency, the most of manufactures employ four photomask processes currently. However, along with the large-scale panel tendency all the related manufactures are pursuing nowadays, a higher cost problem brought by a larger photomask is a significant challenge for the manufactures to be confronted and to be solved.